Amphibians

There are multiple animal exhibits in the Naturally Wild Swap Shop. One of them is home to two Houston Toads: Tina Toad and her friend, Mr. Toad.

The Houston Toad is one of Texas’ most imperiled species. Its range was formerly known to include 12 counties in Texas, but it is now only in a few counties in east-central Texas. The largest remaining populations are found in the Lost Pines region of Bastrop County.

The Houston Zoo has a 1200 square foot Houston Toad quarantine facility, managed by two full-time

Tina Toad’s egg strand

Houston Toad specialists, that serves as a location for the captive breeding and head-starting of wild Houston toad egg strands for release. Part of the Houston Toad specialist’s job is to count the eggs in each egg strand!

The egg strand after it has been counted

Look at the pictures in this post. What you are seeing is a picture of one of Tina the Houston Toad’s egg strands. The version with the white dots is an example of how the eggs are counted and marked as they go through the photo of the egg strand.

We recently had a contest in the Swap Shop to guess how many eggs were in the strand. The total in the strand, according to the toad keepers, was 8,533. Our closest guess was from Isabel S. who guessed 8,600. For her expertise in counting toad eggs, she received 100 points to spend in the Swap Shop!

Don’t know about the Naturally Wild Swap Shop? Click here for more information.

Some of the most amazing things about Texas are all of the fabulous native wildlife species. Texas has a long and rich natural history – from the Horned Lizard, to the Nine Banded Armadillo, to the state flying mammal, the Mexican Free-tailed Bat. But, some of our native species are in jeopardy.

Meet Tina Toad. She is one of the Houston Zoo’s ambassador animals and is a retired Houston Toad that was a part of the Zoo’s breeding program. After laying over 10,000 eggs (yes, Moms, I said 10,000), she was retired and came to live in the Naturally Wild Swap Shop. Recently, we were able to get a picture of her with another kind of Texan. Kurtis Drummond, safety with the Houston Texans, came by along with Bethany and Brianna from the Houston Texans Cheerleaders.

The Houston Toad is one of Texas’ most imperiled species. Its range was formerly known to include 12 counties in Texas, but it is now only in a few counties in east-central Texas. The largest remaining populations are found in the Lost Pines region of Bastrop County. Habitat loss, fragmentation and degradation are the most serious threats facing the Houston Toad. Red fire ants can also have a devastating impact by killing young toads and altering local insect and arthropod populations which the toads feed on.

Their habitat is associated with deep sandy soils within the Post Oak Savannah of east central Texas. The toads burrow into the sand for protection from cold weather in winter and hot dry conditions in the summer.

Breeding season peaks in March and April. Large numbers of eggs are produced; however, each egg has less than one percent probability of survival. Eggs hatch within seven days and tadpoles turn into tiny toads in as little as fifteen days.

The Houston Zoo has a 1200 square foot Houston Toad quarantine facility, managed by two full-time Houston Toad specialists, that serves as a location for the captive breeding and head-starting of wild Houston toad egg strands for release. Approximately 1,950 Houston toad tadpoles were transferred from the Houston Zoo to Texas State University for release into native habitat as of January 2015. The zoo also has established a collaborative, conservation-based Houston Toad research project with local universities including Rice University and the University of Saint Thomas.

To meet Tina the Houston Toad, come by the Naturally Wild Swap Shop between 9AM and 5PM any day the Zoo is open.

Amphibians all over the world are affected by several factors causing alarming declines in populations. The most concerning issue currently is Batrachochytrium dendrobatidis more commonly known as chytrid or Bd. Bd is an aquatic epizootic(an epidemic of a disease event in nonhuman animals) fungus which causes a disease known as chytridiomycosis. This fungus attaches itself to the skin of an amphibian restricting proper intake of oxygen and osmoregulation, which are two very important duties of amphibian skin. In 1998 the first case of chytrid was documented in Australia, and then in 2004 Dr. Karen Lips documented chytrid in Central America. Dr. Lips noted that populations decline very rapidly, sometimes over just a few weeks! This fungus occurs on every continent where amphibians occur and has caused catastrophic declines or extinctions of almost 200 species of amphibians, even in pristine habitat in just about 30 years.

A species which you may see on exhibit in the Reptile and Amphibian House, the Panamanian Golden Frog, is now a functionally extinct species in its native range. This is due primarily to the chytrid fungus. This fungus much like every other living organism has a “breeding season”, if temperatures are too hot or too cold it lies dormant, but when the temperatures are just right like where the Panamanian Golden Frogs live the fungus multiplies and spreads non-stop. This doesn’t allow for amphibian populations to “hop” back and therefore wipes out an entire species in some cases, in less than a year. Several theories of where this fungus originated, how it has spread so rapidly, and how to control it have been discussed but to date no solid answers have been found.

Other factors, which include pollution of soil and waterways due to pesticides used on lawns and gardens and the improper disposal of batteries, habitat loss for palm oil plantations, paper manufacturing or even wooden chop sticks, global warming, and over collection for the food and pet trade, also play a significant role in amphibian declines worldwide. Many scientists, researchers and biologists agree that amphibians may be the next mass extinction since the dinosaurs some 65 million years ago.

Batteries, Wildlife, and How You Can Take Action

The Houston Zoo cares about animals in the wild, and is taking steps to ensure that everything we do on Zoo grounds is done with the environment and wildlife in mind. If you have a surplus of used batteries, be them alkaline or rechargeable, you can take them to your local recycling center to ensure that the remaining chemicals and substances don’t harshly affect the wildlife that’s directly outside your doors!

Any battery that is disposed of in a landfill (like if you toss them in your normal trash), or that finds its way into the environment, has the potential to leak its old chemicals into the soils and waters that wildlife like amphibians call home.

Because amphibians like frogs, toads, even salamanders, have skin that can easily absorb liquids found in damp soils or the waters and streams they frequent, they can get sick from things like leaking batteries. Often, harsh or foreign chemical interactions can affect populations long-term by changing the behavior of animals, affecting female or male reproductive abilities or even influencing the development of eggs.

The Zoo works to help our local amphibians by recycling our alkaline and rechargeable batteries with a company that specializes in battery disposal. You can do the same by finding your local recycling center; if you’re in Houston you can go to the Westpark Consumer Recycling Center and they will take most options besides alkaline. You can also recycle more than the typical AA, AAA, C, and D batteries – items like power tools, cars, small electronics like tablets or smart phones, hearing aids, watches, and all manner of things take a variety of batteries.

By using rechargeable batteries you can also ensure that the materials that were mined to make your batteries last for a much longer time period than with single-use alkaline batteries. Rechargeable batteries will go dull over time, but you can get multiple uses out of them and lessen the stress on the environment by finding products and items that you can use over and over before recycling!

How Our Staff Recycles Batteries at the Zoo

On Zoo grounds we will often offer recycling information that you can see when you visit. We recommend you take your batteries to a local recycling center to ensure they don’t end up in landfills that can encroach on the space of wildlife as well as affect the soils and waters amphibians and other animals call home.

Behind the scenes, our staff utilize a special battery drop-off for spent batteries. By encouraging staff to recycle these items the Zoo is able to see how many batteries we use as an organization, and how many we use that are rechargeable! Alkaline batteries are not rechargeable, so taking a look at our staff battery needs shows us where we could potentially get more rechargeable batteries rather than single-use alkaline batteries. We can also weigh our battery recycling over time and see how much space we have saved in landfills and how many batteries have been prevented from harshly affecting our wildlife habitats.

Be Safe When Collecting Batteries for Recycling

Alkaline: these are more often the common batteries like AA, AAA, C, or D as well as 9-Volt. Do not store any of these batteries together without packaging. Once they have been used there is still potential for them to ‘pop’ open as there are residual chemicals that can be discharged and react with other batteries they are near. This could cause injury if someone is nearby. The 9-Volt batteries are commonly used in your fire alarms and are properly prepared for the recycling center by putting duct-tape over the positive and negative transistors (basically, the top two prongs need to be covered so they don’t come into contact with other batteries). Note that some centers do not accept alkaline batteries for recycling.

Rechargeable: these batteries are widely used in items like power-tools, phone batteries, laptop batteries, or even your more common AA, AAA, C, D, and 9-Volt options. There are no alkaline battery options that cannot be replaced with rechargeable options. You will find rechargeable batteries in forms of Nickel Cadmium (NiCd), Lithium-ion (Li-ion), and Nickel Metal Hydride (NiMH). All of these batteries have the potential to get hot and should be packaged separately from each other in preparation for recycling; Li-ion should be particularly tended to in ensuring there is no other metal or battery contact once discharged.

Since it’s almost Valentine’s Day we here at the Zoo would be remiss if we didn’t talk about how amphibians find that special someone.
Amphibians are probably the most commonly heard vertebrate on the planet and this is due to the wonderful chorus that frogs and toads provide every year in the spring and summer, at least in North America.

Each year large groups of males congregate at perennial or vernal pools, ponds, or streams and sing for their mate. The larger the chorus of bachelor frog the more attractive it is for the ladies. Yet, even if multiple different species of frogs or toads are calling at one pond, each species of frog and toad have their own unique and identifiable call. This is how many researchers calculate populations of amphibians by listening to each individual species chorus and count the number of males calling.

This bombastic strategy isn’t the only way amphibians find their mates. Some frogs and toads are unable to call loud enough due to other noise in their environments such as fast moving streams or rivers. These frogs and toads employ the strategy of semaphoring, which is basically flagging or waving of either their front or back legs to stake claim to a territory or attract a mate.

Amphibians are an extreme and versatile group of animals. They come in three main body types yet they exhibit some extreme variation in size, shape, and function.

Size:

The largest frog or toad in the world is the Goliath frog (Conraua goliath) native to West Africa. This frog measures in at 12.6 inches and weighs up to 7.17lbs. The Goliath frog is followed in sized by the Cane Toad (Rhinella marina) and African Bullfrog (Pyxicephalus adspersus). Yet the world’s biggest amphibian title is held by the Chinese Giant Salamander (Andrias davidianus). This behemoth comes in at a whopping 5.9ft long and weighs in at a hefty 110 lbs. Though its size may be impressive, it has made it a target in its native China as a popular luxury food item and its use in Traditional Chinese Medicine (TCM). The world’s smallest amphibian Paedophryne amauensis (no common name given yet) from Papua New Guinea, also holds the title of the world’s smallest vertebrate. Measuring in at an incredibly small 0.30 inches it beat out the current record holder, a fish from Indonesia by 0.0079 inches. This amazing amphibian can fit very comfortably inside the diameter of a dime.

Amphibians come in many extreme shapes, all of which help them to survive in their natural habitat. The most unknown group of amphibians has to be the caecilians; in appearance they look like scale less snakes or large segmented worms. This is augmented by the fact that most subterranean caecilians, have no or small vestigial eyes and weird tube like tentacles that come out of their nose. Caecilians aren’t the only amphibians that look extreme though, take the Indian purple frog (Nasikabatrachus sahyadrensis). This frog is again almost completely subterranean; it even eats underground, yet when the monsoons come to the Western Ghats of India these frogs surface to call and mate in the fast moving rivers and streams that are formed from the rains.

Though size and shape are an extreme in which we categorize amphibians, others in this order are equally extreme in the way in which they behave and survive in their natural habitats while dealing with extreme conditions. Spadefoot toads cocoon under the ground in the deserts until the rains return and it is incredible that amphibians survive up north where it is cold almost 6 months out of the year. How do they do it? The North American wood frog (Lithobates sylvaticus) handles this situation by allowing itself to freeze solid by protecting its blood and vital organs with anti-freezing peptides produced by it and from the prey it eats. The same is true of frogs that are exposed to extreme heat yet have no means to escape it by burrowing. The giant waxy monkey tree frogs (Phyllomedusa bicolor) are able to produce their own natural sunscreen and wipe it all over their bodies to prevent drying out through desiccation. Finally what’s more extreme than an animal that doesn’t breathe on land using lungs? There is a whole family of salamanders called Plethodontidae that don’t have any lungs at all. They breathe through their skin exclusively and are one of the largest families of salamanders in the world. The most amazing thing is most of these salamanders are located here in the United States.

Before we get to that, let me throw this out there. There are five taxonomic classes of vertebrate (having an internal skeleton) animals. These are fish, amphibians, reptiles, birds, and mammals. Historically, amphibians and reptiles have been grouped together, often resulting in confusion as to what each group contains. Amphibians include frogs and toads, newts and salamanders, and caecilians. Crocodilians, lizards, snakes, turtles, and tortoises are reptiles.

Houston Toad

The words “frog” and “toad” are not strict definitions. In general, frogs have smooth skin and are more likely to stay close to water, while toads usually have dry bumpy skin and can be found further from water. Also, frogs jump and toads do cute little hops. Same deal with “newt” and “salamander.” Newts are a kind of subgroup of salamanders and are usually aquatic as adults. The third kind of amphibian that you’ve probably never heard of is the caecilian. These look basically like large earthworms and most are burrowers so aren’t seen very often. Some are quite colorful and one can even grow to almost 5 feet!

Caecilia species Loreto Peru. Photo credit: Dante Fenolio

So that is what amphibians are. Stay tuned over the next few weeks of “Amphibian Month” to learn some interesting, and some downright weird things about them.

The Houston Zoo is excited to welcome a new intern who comes to us all the way from Kenya, in East Africa. Gilbert Sabinga is in the United States as participating in the Community College Initiative Program (CCIP). The Community College Initiative Program is a program of the U.S. Department of State, administered by Northern Virginia Community College on behalf of the Community College Consortium (CCC) in partnership with Houston Community College. While participating in this program, he will join us at the zoo as an intern to learn all about what a modern-day zoo is like! Sabinga is already part of the conservation community as he has been working with Save the Elephants in Kenya for over 8 years. He will be documenting his experiences at the Zoo and we will share his thoughts with you here on our blog!

Sabinga writes:

Houston Zoo is the nature in it’s wildest. Every day coming to the zoo it offers me a new chance to get up close from wildlife around the world, and learn close facts about the animals. This time I was introduced to toads!!!! The little I knew about the toads is valuable part of our outdoor heritage. Most of people probably don’t give them much thought, and rarely credit what we consider lesser life not with emotions big as ours; but we need these amphibians to control destructive insects and to offer their voices to the sounds of spring and summer nights. Just hearing or seeing them adds to our enjoyment of outdoor joy and makes our environment beautiful. I visited and got to help in the toad department under the instruction of Tyler Parker, who never get tired of me asking questions about toads. He really taught me much on toads and expanded my knowledge about the toads especially Houston toads.

Today, with species threatened and habitats disappearing worldwide, the Houston Zoo is playing a new role in conservation: the Zoo is expanding their efforts far beyond keeping animals alive in captivity. An example of this is the toad quarantine facility that serves as a location for captive breeding and head- starting of Houston toads eggs stand for release in to the wild, and this facility is managed full-time by Houston toad specialists who care for the toads and work closely. I never thought of how great this is wow! Credit to toad keepers.

The best part is that we would all love to think that wild animals in reality are at least a little bit like they are in National Geographic movies – cute, cuddly and happy to be in human company. Certainly toads can get used to human caretakers. Dr. Lauren Howard held one told and I was surprised that the toad did not struggle and even closed its eyes! I was wondering is it love? Or, the warmth of Lauren’s hand, or cues from the toad that it enjoys the care. We all need to care for these magnificent local Texas creatures.

Amphibian species are now on the verge of extinction. How do we save them?

– Toads like to take their time crossing the road…give them a brake! Roadkill is a significant cause of toad and frog mortality in many parts of the world. So drive slower on wet nights. Help a frog or toad cross the road (careful: don’t cause an accident or get squashed yourself).

– If you are building a pond, and want to support a healthy toad community, do not stock fish in it–even native species. Fishless ponds always tend to have a higher amphibian biodiversity than do ponds with fish.

– Most of the products we use in our daily life, and even the things we take for granted (food, water, electricity) have been removed from their natural place in the environment. We therefore offer the following suggestions on how you can reduce your ecological footprint: Turn off your air conditioning when it’s not in use. Take a shorter shower. Put a lid on that pot of boiling water. Turn off your lights. Print on both sides of the sheet of paper. Turn your jacuzzi off when it’s not in use. Going for a picnic? Don’t use styrofoam plates; most supermarkets sell biodegradable corn plates.

For more information visit; conservation@houstonzoo.org

Point to remember; Toads may be begging for their environmental freedom!!!

The Houston toad team at the Houston Zoo has been working up a storm this spring – a storm of Houston toad eggs! As of this writing, the team has bred 23 groups of adult Houston toads (the groups consist of either one female and one male or one female and two male) since the middle of February using assisted breeding methodologies. In total, we have produced ~80,000 Houston toad eggs!! This is more than twice as many as we produced last year and is a tremendous success for our program!! However, I’m sure you are all wondering just what in the world are we doing with all of those eggs??

Each and every one of the Houston toad egg strands produced at the Zoo going back to the wild to help augment the wild population. Researchers from Texas State University (TSU) are strategically placing the egg strands in two counties, Austin County and Bastrop County, which are in the historic range of the Houston toad. Both of these counties still harbor small, wild populations of Houston toads that are being monitored by TSU and USFWS.

Researchers from TSU and Houston toad staff and interns are placing the eggs inside protective, wire cages as the strands are placed into the release ponds. Cages? What are those for? One of the biggest complications for the Houston toad recovery effort is that everything LOVES to eat Houston toads – especially their eggs! Birds, fish, aquatic invertebrates, raccoons, you name it; they all love to snack on tasty toad eggs. The cages prevent these hungry critters from feasting on these precious, endangered egg strands, helping to ensure that many of these eggs will survive to make tiny toadlets!

TSU researchers are monitoring each of the release sites and are on the lookout for Houston toad tadpoles and metamorphs. Are the cages working? Are the eggs going to hatch? Stay tuned to find out!

The Houston toad team spends countless hours performing the traditional tasks associated with caring for animals. These tasks includes the cleaning, feeding, medical treatments of the Houston toads, as well as water quality testing, care of the invertebrate cultures, and the general maintenance of the toad facility. However, did you know that the team is also responsible for being toad “match-makers” during the breeding season? Yup, that’s right. Not only are we handy with pH testing strips and power drills, we can also provide professional dating recommendations to Houston toads (now try writing that up on YOUR résumé!)

Like many other endangered species, the breeding of Houston toads is managed a Species Survival Plan (SSP), which is a document produced by the Association of Zoo and Aquarium’s Population Management Center. The SSP takes into consideration the known genetics of a group of animals and makes recommendations as to who the animals should be paired with. With these guidelines in hand, the Houston toad team evaluates each individual toad from a group of toads approved for breeding, and assesses their health and size. Breeding pairs (or triplets, often one female and two males) are then grouped accordingly. This year we evaluated and paired over 170 individual toads!

Breeding Houston toads is not as easy as placing a male and female toad together. In fact, it is very difficult (but not impossible) to encourage natural breeding captive environments. Here in the toad facility, we use a hormone assisted breeding protocol to ensure successful breeding in our Houston toads. This protocol takes place over the course of several days, and requires a concerted effort between the Houston toad team and the zoo’s veterinary staff.

It would be impossible to breed all 170 toads at one time, so this spring we are staggering the breeding attempts over the course of two months and setting up 6-8 breeding pairs a week. We are happy to announce that our first round of breeding (that ironically began on Valentine’s Day) was a huge success! Out of the 8 total pairings set up, we produced 7 strands which totaled around 27,000 eggs!

So now that our matchmaking efforts were a success, what’s next? Stay tuned to the next blog post to find out what we are doing with all those toad eggs!

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